Well, I lost compression, and just started tearing into it last night. Just to recap from previous threads- I just bought this ody a couple months ago. The stock fuel tank was pretty crusty, so I swapped on a gravity tank and it ran for a bit, then nothing. I later discovered that the main carb jet was a #138, so it was probably a bit lean. I had spark, had fuel, checked the compression and had nothing.

I'll try to attach the pics here-

head-

cylinder-

another piston pic-

It's still on it's original bore.

So, help me out here guys. Did it get too hot running lean?

need more, better pictures

but i would hazard a guess and say the exhaust port caught the ring and the rest happened from there

that head looks from the pictures to be a gonner-did you find all the parts that caused that damage by chance?You may-IMO-want to split that bottom end and make sure you don't have any pieces in there ---

There is a little damage to the exhaust port like the ring could have snagged on it. Sections of the top ring are gone, along with piston pieces above and below where the top ring was. The top of the piston and the head are nicked up pretty bad and have small chunks embedded. I couldn't find any pieces anywhere. I think they were chewed up and spit out. -?

Should I send off the cylinder to somebody to bore and taper the exhaust port, or should any local machine shop be able to handle that?

Could the nicks in the head be smoothed out? Clean up the chamber and lower the deck height a little to get the C/R right? Odysseysalvage has used heads for $75, so maybe it's not worth trying to clean this one up. -Or maybe it's time to go watercooled?

hmmm.... I guess now is the time to make some choices. I definately want to tweak it a bit as it goes back together, get some more outta it.

if you have a local shop you trust just tell them what you want. I am a cheap bitch that wouldn't worry about the head, just smooth out the best you can and roll with it or take it with the jug and new piston (if you know what piston it needs) to a local builder and he should keep it under $100. for the work.

do make damn sure nothing is in the bottom end, a tiny piece hiding in an oil port or in a bearing will ruin a day, i usually use kero or diesel then finsh with a pre mix rinse.

I'm just trying to get a parts list together- piston & rings, gaskets, carb jets... I'll go ahead and do the clutch.

Save the head? I'll clean it up as best I can and see.

What else should I be looking at? I agree about splitting the case and making sure it's clean, anything else while I'm in there?

Anything else for the parts list? I'm gonna try to call Randy at OS tomorrow, order up everything I think I need and get this thing back up and going ASAP.

Thanks guys.

Read through the CSI's it will give you an idea what you might find once inside as well as hints and tips...

http://pilotodyssey.com/CSI.htm

UPDATE:

I got it rebuilt. 1st bore, new wiseco piston and rings, relieved the exhaust bridge, drilled the oiling holes, and cleaned up the head as best I could, split the head gasket to regain C/R. I also clean up the ports a little, added boysenn reeds, reed spacer, 102c clutch.

I'm still having some issues though. It runs great for a few minutes, then sputters out. I talked to Randy at OS for a while, was going to order a new carb- thinking it was carb issues and would like to upgrade anyway. Randy said to check the coil and CDI (Capacitor Discharge Ignition) first. Both failed. So now I'm looking to get those and see what it does. Any upgrades or aftermarket options for either? Coil is on the way from Service Honda, but they say the CDI (Capacitor Discharge Ignition) is discontinued.

I got to run it for a little bit, though. Trying to take it easy and wear it in. But it definately has a lot more balls than before. I can't wait to get these issues sorted out and ride it.

Once I get it running well the next upgrades are carb and pipe.

before you buy a CDI (Capacitor Discharge Ignition) find out if there is anyone near you that has a known good CDI (Capacitor Discharge Ignition) to try... Where are you at? City/state...
Invest in a watercooled head since your old head is boogered up!!! It will be a big help in the longevity of the 350... Got to keep it cool... Install a Turbo-fan like I did that will help also... a bigger carb is good but I would get watercooled head up first... have you done airbox mod???

I'm outside of Raleigh, NC. I've got a buddy nearby with a running Ody to swap parts off of, but I checked the CDI (Capacitor Discharge Ignition) and coil per the manual, measuring resistance point to point, and it doesn't meet tolerance anywhere, has no resistance across some points. I'll check with him about swapping the CDI (Capacitor Discharge Ignition).

Any upgrade for the CDI (Capacitor Discharge Ignition)? -or is my only option a used one from Randy?

The head looks pretty good now. I should've taken some pics before I reinstalled after a few hours of polishing. I'd like to go watercooled, right now I just want to see it run.

Airbox mod will be up soon. I've just left the top off while breaking it in and trying to get it running.

BTW, I did split the bottom end and cleaned it thoroughly.

I think your kinda answering your own question and solving your own problem, I would resolve the "no resistance across some points" problems before I bought any parts, CDI (Capacitor Discharge Ignition)'s seldom if ever go bad but they are the most replaced items.

How do you resolve it, though? I'm checking per the table in the manual, page 14-3. I checked it with 2 different meters, and they read "open" or "0" across points where they should have resistance per the chart. I'll swap it with my buddy's and see if it works, but this one doesn't check out. I really don't want to buy a CDI (Capacitor Discharge Ignition) ($$$).

Watch your jetting closely, you just added a lot of air to your fuel mixture by removing the lid!!! Main #1 reason ody 350's go poofkaboom!!!
That and they don't cool well behind the seat...

Gotcha Turbo. I did fatten it up a bit. Right now I just can't get it running long enough to do a plug chop.[/quote]

I just left Savannah Ga. I see your in NC... I will try to bring the Ody out next time I head this way... I want to see what all the excitement is all about in Durahmtown Plantation???

HI Kevin. Sorry to hear about your motor (( Internal Combustion Engine ? )). Looks like your coming along with it though. I just wanted to let you know I have a head if your interested. It was pulled from a running Odyssey. I removed it to install a WC head. $40 plus $12 to ship in the US. PM me if your interested. Its just collecting dust on the shelf...

PM sent. Thanks.

Turbo- yea that Durhamtown place sounds sweet. I've never been, never talked to anyone who has. There's another place in SC called Carolina Adventure World that sounds cool, too. I've got a bunch of buddies and we were planning to do a good riding road-trip sometime this spring/summer. We still gotta figure out where.

I did get that head from STIX9567. Looks good. It'll be installed shortly. THANKS MARC!

I'm still struggling with the same issue, though. It starts up fine, idles great, runs good with plenty of power, but just dies after a few minutes. I did swap the coil with a new one, replaced the float needle, and checked the float level again. It started doing this before the rebuild though. Now it's just more predictable.

I'm gonna clean all the ground connections up real good and see if that helps. If that doesn't do it, I'll take it to my buddy's house and swap his CDI (Capacitor Discharge Ignition) in there. I'll get it figured out eventually.

Have you checked and changed your fuel filter?
My Oddy had the same "after a while power loss" symptoms while under full throttle.
It starves of fuel under it's highest demand due to blocked filter and hence restricted supply.
Slow down and it catches up till the filter empties again...Baz

When it dies verify if you have fuel in the carb or not.

Might have the rusty tank syndrom???